5D3 vs 6D AF in low light

[dlleno]

Saying things like "I shoot alot of low light" doesnt mean anything really...

...I for one hardly take my flash with me - the camera takes great pictures in low light with some help from lightroom, but getting it to focus sometimes is a problem.

so....what IS low light to you? are you approaching the EV limits of the AF system, or well within them? These tests are all are very enagaing, but if we could express the level of light in terms of the EV numbering system understood by the photography world, it would be more meaningful. Can someone please explain to me why this is either difficult or unattractive?

Most of the the tests in the video were reasonably done. For example, the guys did a good job of exposing the "snappy" (5D3) versus "heasitant" (D800) AF in the studio, which was revealing, to be sure, especially when acknowledged by the confessed Nikon shooter. Notice he didn't even say anything like "when side by side there is really no important difference", as he did in the shadow DR comparison. for the studio lighting condition the AF performance of the 5D3 was a definate, measureable, and meaningful advantage in real situations.

The low light focusing shootout was disapointing to me because it didn't really test the capabilities of the AF system's thesmselves in low light. All they did was point out that the D800 has an AF assist capability that is useful at reasonable portrait distances when the visible AF assist light is acceptable. Good information, to be sure, but low-light shooters don't necessarily want visible AF assist! What they should have tested is situations where AF assist is either impossible (due to distance) or undesired.

Back to the subject at hand, are you all saying that the 5D3's AF performance in low light (without flash attached) isn't commensurate with the situation, i.e. shutter speeds that would be typical, subject movement etc? Unless I've missed something, the only consistent performance issue meaningfully described here is that camera does not utilize the AF-assist beam from the flash very well.

 

[skitron]

Just a follow-up to this...

After experiencing my 200L f/2.8 and how well it focuses in low light vs my 100L with 5D3, I read in the 5D3 manual that the 200L is in AF group A while 100L is in group C, meaning the 200L uses all of the dual cross f/2.8 AF sensors while the 100L uses none of them.

So this explains things since according to p95 of the 6D manual, the 100L apparently uses the maximum capabilities of the 6D center point whereas on the 5D3 Canon has limited the 100L to use only diminished center point capabilities.

Given this, using the 100L to compare the 6D and 5D3 center points was not an apples to apples comparison. And IMO if Canon allows the 100L to use the max capabilities of the 6D center point, Canon needs to offer a firmware fix for the 5D3 and 100L...

 

[EvilTed]

It also looked like he was using a 50mm 1.2 L for the low light tests.
This lens isn't sharp in good light wide open, so it's hardly surprising that the Nikon was better

An interesting and pretty fair review.
Add to this the AF problems that are plaguing D800 users and I'm glad I made the switch to Canon.

ET

 

[hemidesign]

folks, don't forget about Bryan Review from the-digital-picture website.

"I can focus the 6D's center point on a subject with reasonable contrast down until auto exposure gives me a setting of 160 at 10 seconds and f/2.8 (really dark) with the Canon EF 24-70mm f/2.8 L II USM Lens mounted (note that the 6D's metering range spec is listed at EV 1-20). The Canon EOS 1D X's center point could not focus on the same subject with the same lens mounted. Note that the 6D focuses very slowly under these dismal lighting conditions - but locking slowly is far better than failing to lock."

"Made to focus in very low light condition: EV-3 is the strongest low light AF performance of any Canon AF system at Canon EOS 6D review time. EV-3 is the equivalent of moonlight."

So..1DX has the same AF system as the 5Dmk3.. so 6D does a better job focusing at dark conditions.. better FROM ANY CANON CAMERA TO DATE!

 

[dlleno]

I wish folks would be specific in test results on this topic, as many here have. for eample, has anyone noticed that in this video:

Canon 6D Vs. 5D Mark III Hands On Review

at about 10:50 the reviewer shows a still life shot taken by a 5D3 and 6D at a light level Just short of -3EV? yes, just short of -3EV. ISO 200 15 seconds f/2 is approximately -3EV, so a 13 sec exposure indicates less available light than -3EV, assuming the photo is properly exposed.

this is beyond the AF sensitivity specification listed for the 5D3, which is -2EV for all focus points. It is even (very slightly) beyond the AF sensitivity spec for the 6D, who's center point is spec''d at -3EV sensitivity . Anyway, the reviewer indicated no problems whatsoever with AF for either camera at that light level. However, here's the "but": he didn't say how long it took to achieve AF lock for each camera and he didn't say at what distance the lens was focused prior to locking on the subject. :-(

 

[Magnardo]

Nice video but,.....I have never met or heard anyone that says "on that"as much as this guy.
It seems he is doing it after every sentence.

 

[tortilla]

Most of my photography with the 5D3 is in low light and I find the focusing to be excellent, at least as good as any other camera I've used in the past 10 years. And most Canon flashes have a built-in autofocus assist light, so I don't know why anyone would need a laser assist.

When shooting low key portraits, models don't like it to be dazzled by the assist flash.

 

[Marsu42]

When shooting low key portraits, models don't like it to be dazzled by the assist flash.

Animals often also aren't very enthusiastic about getting the af assist in their eye (and that's why I usually focus) - unfortunately the 60d (af rated up to +0.5lv) uses af assist very often, so I'm looking forward to the 6d.

 

[Zlatko]

Most of my photography with the 5D3 is in low light and I find the focusing to be excellent, at least as good as any other camera I've used in the past 10 years. And most Canon flashes have a built-in autofocus assist light, so I don't know why anyone would need a laser assist.

When shooting low key portraits, models don't like it to be dazzled by the assist flash.

I was responding to the statement that the 5D3's ability to focus in low light is atrocious. On the contrary, I've found it to be excellent in low light, and that is without any autofocus assist light. However, an autofocus assist light can be used if needed. It is not an "assist flash" and doesn't "dazzle". To clarify, it is the red AF assist light available on most Canon flashes and on the ST-E2. The red AF assist light can be used for AF assist only, with no flash being emitted. The flash is on, but set to not fire. It's not ideal, and it's usually not necessary, but it's available if needed.

 

[J.R.]

Zlatko ... Thanks for the info

 

[dlleno]

Zlatko can you express what you mean by "low light" in terms that can be correlated to the results of others', as well as the published specifications for AF sensitivity? short version: What does "low light" mean to you in terms of EV(100)?

 

[Zen]

The definition of "low light" is critical to these conversations, and because it is so subjective, the debate is almost meaningless. In my case, I'm sitting here in my den, appx. 12' by 24', with one 100 watt tungsten bulb in the corner lamp. The lamp is behind me and when I focus on the opposite wall, containing well filled book cases of aged cherry, my 5D3 clicks to focus quite easily and without any delay. I call this low light, and have no problem at all. I cant imagine a faster or sharper focus! And when I take the time to set the custom WB after use of a gray card, the images come out perfectly.

Perhaps my standards are lower than others, but I couldn't be more satisfied with my 5D3. ;D

Zen

 

[Marsu42]

The definition of "low light" is critical to these conversations

Furthermore "achieving focus" needs definition, because in problematic lighting conditions the camera will take more time to focus - I hope the detailed dpreview.com 6d review will tell us at last if the -3lv rated 6d is getting a focus lock faster @-2lv than the 5d3 which is maxed out in this level.

 

[J.R.]

The definition of "low light" is critical to these conversations

Furthermore "achieving focus" needs definition, because in problematic lighting conditions the camera will take more time to focus - I hope the detailed dpreview.com 6d review will tell us at last if the -3lv rated 6d is getting a focus lock faster @-2lv than the 5d3 which is maxed out in this level.

It should based on the theory. As I normally shoot in the evenings / night, I am really looking at the 6D as a replacement for the 7D if this is confirmed. Too bad in my country there is no option of renting the 6D or I would have checked it out by now.

For me the AF issues have arisen only in near darkness situations. The AF seems to continually hunt from end to end. Otherwise the AF system is near perfect.

 

[dlleno]

why is it so hard to state the light level in terms of EV(100)? if you have taken a picture, that is exposed properly, you have the necessary information

 

[Zen]

I wonder . . . do we expect the camera to "see" better than we ourselves can? For example, I can barely make out shapes in "near dark" situations, yet some expect the camera to do better than that. Is that logical? :-\

Zen

 

[dlleno]

I wonder . . . do we expect the camera to "see" better than we ourselves can? For example, I can barely make out shapes in "near dark" situations, yet some expect the camera to do better than that. Is that logical? :-\

Zen

we expect the camera to af in the light levels specified by canon, not those specified by our eyes. why is it so difficult to express the light levels of interest in the terms specified by canon? thats the comparison of value.

 

[Zlatko]

Zlatko can you express what you mean by "low light" in terms that can be correlated to the results of others', as well as the published specifications for AF sensitivity? short version: What does "low light" mean to you in terms of EV(100)?

Sure, looking at recent photos in Photo Mechanic, I would say that typical "low light" photos were in the range of EV 1.2 to EV 4.0. These would be interior scenes at night, photographed without flash and without an AF assist light. Those EV numbers correlate to these exposures:
EV 1.2 = ISO 3200, f/1.2, 1/50th
EV 4.0 = ISO 800, f/1.6, 1/50th

 

[RLPhoto]

Lol. I just used my 5D3 strobist with no AF assist beam with just a distant street lamp for a source of light to AF. If the 6D is any better, wow but the 5D3 is still the best AF camera I've ever used.

 

[dlleno]

Zlatko can you express what you mean by "low light" in terms that can be correlated to the results of others', as well as the published specifications for AF sensitivity? short version: What does "low light" mean to you in terms of EV(100)?

Sure, looking at recent photos in Photo Mechanic, I would say that typical "low light" photos were in the range of EV 1.2 to EV 4.0. These would be interior scenes at night, photographed without flash and without an AF assist light. Those EV numbers correlate to these exposures:
EV 1.2 = ISO 3200, f/1.2, 1/50th
EV 4.0 = ISO 800, f/1.6, 1/50th

Ahh thank you. So 3-6 stops brighter than published minimum AF sensitivity